1. Field of the Invention
The present invention relates to concrete anchors used for constructing tilt-up concrete walls which are cast in a horizontal position, and in particular to an adaptor bar for reversibly converting two single anchors into a double anchor.
2. Discussion of the Prior Art
Many buildings are constructed utilizing concrete wall slabs which are cast on sight in a horizontal position. The slabs are then tilted up to a vertical position to form a building wall or the like. Typically, anchors are imbedded in the walls during the casting process for use as lifting points in raising such tilt-up walls. U.S. Pat. No. 4,580,378 entitled "Anchor Assembly For Tilt-Up Wall Section" discloses the construction and method of use of such concrete anchors.
It is often desirable to use pairs of uniformly spaced anchors when hoisting concrete walls. Previously, "double" anchors have been constructed by welding a steel rod between two "single" anchors to permanently attach them together with a fixed spacing. This arrangement, however, is costly to fabricate. It requires both double and single anchors be inventoried. Because different wall thicknesses require different height anchors, a variety of heights of both double and single anchors must also be stocked. If a double anchor having two different heights is desired, it must be custom manufactured. Once a double anchor is fabricated, it is difficult to separate it back into two singles if needed. This arrangement requires exact planning prior to setting anchors, and or an extensive inventory of different types of anchors. Because of the inflexibility of this system, an unexpected shortage of a particular type of anchor can lead to costly delays on the construction sight.